Pulmonary pharmacology & therapeutics
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Cigarette smoking has been associated with impaired endothelium-dependent relaxation responses in the brachial and coronary arteries (endothelial dysfunction). The aim of the present study was to determine if the airway circulation is also affected and if airway treatment has an effect on endothelial function. Airway blood flow (Q(aw)) responses to inhaled albuterol as an index of endothelial function were measured in age-matched healthy current smokers, healthy ex-smokers, ex-smokers with COPD and healthy lifetime non-smokers; in the ex-smokers with COPD, the albuterol responsiveness was repeated after a 4-week treatment with an inhaled glucocorticoid/beta(2)-adrenergic agonist combination drug. ⋯ While drug treatment per se did not change Q(aw) significantly, it restored albuterol responsiveness (+67.6+/-11.1%; p<0.05) in the ex-smokers with COPD. Thus, cigarette smoking is associated with endothelial dysfunction in the airway, with a partial recovery of endothelial function after smoking cessation in healthy ex-smokers but not in ex-smokers with COPD. In the latter, combined glucocorticoid/beta(2)-adrenergic agonist treatment restores albuterol responsiveness.
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Pulm Pharmacol Ther · Jan 2007
Randomized Controlled TrialCapsaicin exposure elicits complex airway defensive motor patterns in normal humans in a concentration-dependent manner.
The airway defensive response to tussive agents, such as capsaicin, is frequently assessed by counting the number of cough sounds, or expulsive events. This method does not identify or differentiate important respiratory events that occur in the respiratory muscles and lungs, which are critical in assessing airway defensive responses. The purpose of this study was to characterize the airway defensive behaviours (cough and expiration reflex) to capsaicin exposure in humans. ⋯ At higher concentrations (>50 microM) ER's with one or more expulsive events (ER1) appeared, and the number of CR's with three or more expulsive events (CR3) increased. The decrease in EMG activation and airflow measurements with each successive expulsive event suggests a decline in power and shear force as the number of expulsive events increased. Therefore, the airway defensive response to capsaicin is a complex motor pattern that functions to coordinate ER's and CR's with differing numbers of expulsive events possibly to prevent aspirations and keep air moving to promote clearance.
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Pulm Pharmacol Ther · Jan 2007
Randomized Controlled TrialThe effect of codeine on the Urge-to-Cough response to inhaled capsaicin.
We have shown previously in normal subjects that a sensory measure, the Urge-to-Cough rating, increases at concentrations of inhaled capsaicin that are lower than those necessary to elicit reflex cough. This finding suggests that the Urge-to-Cough may represent an index of the cough response. Research on cough in the human has most often employed challenge with inhaled capsaicin to induce reflex cough. ⋯ These results showed that the initial threshold for responding to capsaicin-induced cough is the perception of an Urge-to-Cough, followed by a motor cough response if the capsaicin is increased above the perceptual threshold. As the capsaicin concentration increases, both the perceptual need to cough and the cough motor response increase. The response of subjects to inhalation of capsaicin consisted of both a sensory component leading to perception of an Urge-to-Cough and motor cough behavior.